VeraCrypt
aboutsummaryrefslogtreecommitdiff
path: root/src/Crypto/Aeskey.c
blob: 948b9238b15e68ee2c26d81f61e096df29c78a2f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
/*
 ---------------------------------------------------------------------------
 Copyright (c) 1998-2007, Brian Gladman, Worcester, UK. All rights reserved.

 LICENSE TERMS

 The free distribution and use of this software is allowed (with or without
 changes) provided that:

  1. source code distributions include the above copyright notice, this
     list of conditions and the following disclaimer;

  2. binary distributions include the above copyright notice, this list
     of conditions and the following disclaimer in their documentation;

  3. the name of the copyright holder is not used to endorse products
     built using this software without specific written permission.

 DISCLAIMER

 This software is provided 'as is' with no explicit or implied warranties
 in respect of its properties, including, but not limited to, correctness
 and/or fitness for purpose.
 ---------------------------------------------------------------------------
 Issue Date: 20/12/2007
*/

#include "Aesopt.h"
#include "Aestab.h"

#ifdef USE_VIA_ACE_IF_PRESENT
#  include "aes_via_ace.h"
#endif

#if defined(__cplusplus)
extern "C"
{
#endif

/* Initialise the key schedule from the user supplied key. The key
   length can be specified in bytes, with legal values of 16, 24
   and 32, or in bits, with legal values of 128, 192 and 256. These
   values correspond with Nk values of 4, 6 and 8 respectively.

   The following macros implement a single cycle in the key
   schedule generation process. The number of cycles needed
   for each cx->n_col and nk value is:

    nk =             4  5  6  7  8
    ------------------------------
    cx->n_col = 4   10  9  8  7  7
    cx->n_col = 5   14 11 10  9  9
    cx->n_col = 6   19 15 12 11 11
    cx->n_col = 7   21 19 16 13 14
    cx->n_col = 8   29 23 19 17 14
*/

#if (FUNCS_IN_C & ENC_KEYING_IN_C)

#if defined(AES_128) || defined(AES_VAR)

#define ke4(k,i) \
{   k[4*(i)+4] = ss[0] ^= ls_box(ss[3],3) ^ t_use(r,c)[i]; \
    k[4*(i)+5] = ss[1] ^= ss[0]; \
    k[4*(i)+6] = ss[2] ^= ss[1]; \
    k[4*(i)+7] = ss[3] ^= ss[2]; \
}

AES_RETURN aes_encrypt_key128(const unsigned char *key, aes_encrypt_ctx cx[1])
{   uint_32t    ss[4];

    cx->ks[0] = ss[0] = word_in(key, 0);
    cx->ks[1] = ss[1] = word_in(key, 1);
    cx->ks[2] = ss[2] = word_in(key, 2);
    cx->ks[3] = ss[3] = word_in(key, 3);

#if ENC_UNROLL == NONE
    {   uint_32t i;
        for(i = 0; i < 9; ++i)
            ke4(cx->ks, i);
    }
#else
    ke4(cx->ks, 0);  ke4(cx->ks, 1);
    ke4(cx->ks, 2);  ke4(cx->ks, 3);
    ke4(cx->ks, 4);  ke4(cx->ks, 5);
    ke4(cx->ks, 6);  ke4(cx->ks, 7);
    ke4(cx->ks, 8);
#endif
    ke4(cx->ks, 9);
    cx->inf.l = 0;
    cx->inf.b[0] = 10 * 16;

#ifdef USE_VIA_ACE_IF_PRESENT
    if(VIA_ACE_AVAILABLE)
        cx->inf.b[1] = 0xff;
#endif

#if defined( AES_ERR_CHK )
    return EXIT_SUCCESS;
#endif
}

#endif

#if defined(AES_192) || defined(AES_VAR)

#define kef6(k,i) \
{   k[6*(i)+ 6] = ss[0] ^= ls_box(ss[5],3) ^ t_use(r,c)[i]; \
    k[6*(i)+ 7] = ss[1] ^= ss[0]; \
    k[6*(i)+ 8] = ss[2] ^= ss[1]; \
    k[6*(i)+ 9] = ss[3] ^= ss[2]; \
}

#define ke6(k,i) \
{   kef6(k,i); \
    k[6*(i)+10] = ss[4] ^= ss[3]; \
    k[6*(i)+11] = ss[5] ^= ss[4]; \
}

AES_RETURN aes_encrypt_key192(const unsigned char *key, aes_encrypt_ctx cx[1])
{   uint_32t    ss[6];

    cx->ks[0] = ss[0] = word_in(key, 0);
    cx->ks[1] = ss[1] = word_in(key, 1);
    cx->ks[2] = ss[2] = word_in(key, 2);
    cx->ks[3] = ss[3] = word_in(key, 3);
    cx->ks[4] = ss[4] = word_in(key, 4);
    cx->ks[5] = ss[5] = word_in(key, 5);

#if ENC_UNROLL == NONE
    {   uint_32t i;
        for(i = 0; i < 7; ++i)
            ke6(cx->ks, i);
    }
#else
    ke6(cx->ks, 0);  ke6(cx->ks, 1);
    ke6(cx->ks, 2);  ke6(cx->ks, 3);
    ke6(cx->ks, 4);  ke6(cx->ks, 5);
    ke6(cx->ks, 6);
#endif
    kef6(cx->ks, 7);
    cx->inf.l = 0;
    cx->inf.b[0] = 12 * 16;

#ifdef USE_VIA_ACE_IF_PRESENT
    if(VIA_ACE_AVAILABLE)
        cx->inf.b[1] = 0xff;
#endif

#if defined( AES_ERR_CHK )
    return EXIT_SUCCESS;
#endif
}

#endif

#if defined(AES_256) || defined(AES_VAR)

#define kef8(k,i) \
{   k[8*(i)+ 8] = ss[0] ^= ls_box(ss[7],3) ^ t_use(r,c)[i]; \
    k[8*(i)+ 9] = ss[1] ^= ss[0]; \
    k[8*(i)+10] = ss[2] ^= ss[1]; \
    k[8*(i)+11] = ss[3] ^= ss[2]; \
}

#define ke8(k,i) \
{   kef8(k,i); \
    k[8*(i)+12] = ss[4] ^= ls_box(ss[3],0); \
    k[8*(i)+13] = ss[5] ^= ss[4]; \
    k[8*(i)+14] = ss[6] ^= ss[5]; \
    k[8*(i)+15] = ss[7] ^= ss[6]; \
}

AES_RETURN aes_encrypt_key256(const unsigned char *key, aes_encrypt_ctx cx[1])
{   uint_32t    ss[8];

    cx->ks[0] = ss[0] = word_in(key, 0);
    cx->ks[1] = ss[1] = word_in(key, 1);
    cx->ks[2] = ss[2] = word_in(key, 2);
    cx->ks[3] = ss[3] = word_in(key, 3);
    cx->ks[4] = ss[4] = word_in(key, 4);
    cx->ks[5] = ss[5] = word_in(key, 5);
    cx->ks[6] = ss[6] = word_in(key, 6);
    cx->ks[7] = ss[7] = word_in(key, 7);

#if ENC_UNROLL == NONE
    {   uint_32t i;
        for(i = 0; i < 6; ++i)
            ke8(cx->ks,  i);
    }
#else
    ke8(cx->ks, 0); ke8(cx->ks, 1);
    ke8(cx->ks, 2); ke8(cx->ks, 3);
    ke8(cx->ks, 4); ke8(cx->ks, 5);
#endif
    kef8(cx->ks, 6);
    cx->inf.l = 0;
    cx->inf.b[0] = 14 * 16;

#ifdef USE_VIA_ACE_IF_PRESENT
    if(VIA_ACE_AVAILABLE)
        cx->inf.b[1] = 0xff;
#endif

#if defined( AES_ERR_CHK )
    return EXIT_SUCCESS;
#endif
}

#endif

#if defined(AES_VAR)

AES_RETURN aes_encrypt_key(const unsigned char *key, int key_len, aes_encrypt_ctx cx[1])
{
    switch(key_len)
    {
#if defined( AES_ERR_CHK )
    case 16: case 128: return aes_encrypt_key128(key, cx);
    case 24: case 192: return aes_encrypt_key192(key, cx);
    case 32: case 256: return aes_encrypt_key256(key, cx);
    default: return EXIT_FAILURE;
#else
    case 16: case 128: aes_encrypt_key128(key, cx); return;
    case 24: case 192: aes_encrypt_key192(key, cx); return;
    case 32: case 256: aes_encrypt_key256(key, cx); return;
#endif
    }
}

#endif

#endif

#if (FUNCS_IN_C & DEC_KEYING_IN_C)

/* this is used to store the decryption round keys  */
/* in forward or reverse order                      */

#ifdef AES_REV_DKS
#define v(n,i)  ((n) - (i) + 2 * ((i) & 3))
#else
#define v(n,i)  (i)
#endif

#if DEC_ROUND == NO_TABLES
#define ff(x)   (x)
#else
#define ff(x)   inv_mcol(x)
#if defined( dec_imvars )
#define d_vars  dec_imvars
#endif
#endif

#if defined(AES_128) || defined(AES_VAR)

#define k4e(k,i) \
{   k[v(40,(4*(i))+4)] = ss[0] ^= ls_box(ss[3],3) ^ t_use(r,c)[i]; \
    k[v(40,(4*(i))+5)] = ss[1] ^= ss[0]; \
    k[v(40,(4*(i))+6)] = ss[2] ^= ss[1]; \
    k[v(40,(4*(i))+7)] = ss[3] ^= ss[2]; \
}

#if 1

#define kdf4(k,i) \
{   ss[0] = ss[0] ^ ss[2] ^ ss[1] ^ ss[3]; \
    ss[1] = ss[1] ^ ss[3]; \
    ss[2] = ss[2] ^ ss[3]; \
    ss[4] = ls_box(ss[(i+3) % 4], 3) ^ t_use(r,c)[i]; \
    ss[i % 4] ^= ss[4]; \
    ss[4] ^= k[v(40,(4*(i)))];   k[v(40,(4*(i))+4)] = ff(ss[4]); \
    ss[4] ^= k[v(40,(4*(i))+1)]; k[v(40,(4*(i))+5)] = ff(ss[4]); \
    ss[4] ^= k[v(40,(4*(i))+2)]; k[v(40,(4*(i))+6)] = ff(ss[4]); \
    ss[4] ^= k[v(40,(4*(i))+3)]; k[v(40,(4*(i))+7)] = ff(ss[4]); \
}

#define kd4(k,i) \
{   ss[4] = ls_box(ss[(i+3) % 4], 3) ^ t_use(r,c)[i]; \
    ss[i % 4] ^= ss[4]; ss[4] = ff(ss[4]); \
    k[v(40,(4*(i))+4)] = ss[4] ^= k[v(40,(4*(i)))]; \
    k[v(40,(4*(i))+5)] = ss[4] ^= k[v(40,(4*(i))+1)]; \
    k[v(40,(4*(i))+6)] = ss[4] ^= k[v(40,(4*(i))+2)]; \
    k[v(40,(4*(i))+7)] = ss[4] ^= k[v(40,(4*(i))+3)]; \
}

#define kdl4(k,i) \
{   ss[4] = ls_box(ss[(i+3) % 4], 3) ^ t_use(r,c)[i]; ss[i % 4] ^= ss[4]; \
    k[v(40,(4*(i))+4)] = (ss[0] ^= ss[1]) ^ ss[2] ^ ss[3]; \
    k[v(40,(4*(i))+5)] = ss[1] ^ ss[3]; \
    k[v(40,(4*(i))+6)] = ss[0]; \
    k[v(40,(4*(i))+7)] = ss[1]; \
}

#else

#define kdf4(k,i) \
{   ss[0] ^= ls_box(ss[3],3) ^ t_use(r,c)[i]; k[v(40,(4*(i))+ 4)] = ff(ss[0]); \
    ss[1] ^= ss[0]; k[v(40,(4*(i))+ 5)] = ff(ss[1]); \
    ss[2] ^= ss[1]; k[v(40,(4*(i))+ 6)] = ff(ss[2]); \
    ss[3] ^= ss[2]; k[v(40,(4*(i))+ 7)] = ff(ss[3]); \
}

#define kd4(k,i) \
{   ss[4] = ls_box(ss[3],3) ^ t_use(r,c)[i]; \
    ss[0] ^= ss[4]; ss[4] = ff(ss[4]); k[v(40,(4*(i))+ 4)] = ss[4] ^= k[v(40,(4*(i)))]; \
    ss[1] ^= ss[0]; k[v(40,(4*(i))+ 5)] = ss[4] ^= k[v(40,(4*(i))+ 1)]; \
    ss[2] ^= ss[1]; k[v(40,(4*(i))+ 6)] = ss[4] ^= k[v(40,(4*(i))+ 2)]; \
    ss[3] ^= ss[2]; k[v(40,(4*(i))+ 7)] = ss[4] ^= k[v(40,(4*(i))+ 3)]; \
}

#define kdl4(k,i) \
{   ss[0] ^= ls_box(ss[3],3) ^ t_use(r,c)[i]; k[v(40,(4*(i))+ 4)] = ss[0]; \
    ss[1] ^= ss[0]; k[v(40,(4*(i))+ 5)] = ss[1]; \
    ss[2] ^= ss[1]; k[v(40,(4*(i))+ 6)] = ss[2]; \
    ss[3] ^= ss[2]; k[v(40,(4*(i))+ 7)] = ss[3]; \
}

#endif

AES_RETURN aes_decrypt_key128(const unsigned char *key, aes_decrypt_ctx cx[1])
{   uint_32t    ss[5];
#if defined( d_vars )
        d_vars;
#endif
    cx->ks[v(40,(0))] = ss[0] = word_in(key, 0);
    cx->ks[v(40,(1))] = ss[1] = word_in(key, 1);
    cx->ks[v(40,(2))] = ss[2] = word_in(key, 2);
    cx->ks[v(40,(3))] = ss[3] = word_in(key, 3);

#if DEC_UNROLL == NONE
    {   uint_32t i;
        for(i = 0; i < 10; ++i)
            k4e(cx->ks, i);
#if !(DEC_ROUND == NO_TABLES)
        for(i = N_COLS; i < 10 * N_COLS; ++i)
            cx->ks[i] = inv_mcol(cx->ks[i]);
#endif
    }
#else
    kdf4(cx->ks, 0);  kd4(cx->ks, 1);
     kd4(cx->ks, 2);  kd4(cx->ks, 3);
     kd4(cx->ks, 4);  kd4(cx->ks, 5);
     kd4(cx->ks, 6);  kd4(cx->ks, 7);
     kd4(cx->ks, 8); kdl4(cx->ks, 9);
#endif
    cx->inf.l = 0;
    cx->inf.b[0] = 10 * 16;

#ifdef USE_VIA_ACE_IF_PRESENT
    if(VIA_ACE_AVAILABLE)
        cx->inf.b[1] = 0xff;
#endif

#if defined( AES_ERR_CHK )
    return EXIT_SUCCESS;
#endif
}

#endif

#if defined(AES_192) || defined(AES_VAR)

#define k6ef(k,i) \
{   k[v(48,(6*(i))+ 6)] = ss[0] ^= ls_box(ss[5],3) ^ t_use(r,c)[i]; \
    k[v(48,(6*(i))+ 7)] = ss[1] ^= ss[0]; \
    k[v(48,(6*(i))+ 8)] = ss[2] ^= ss[1]; \
    k[v(48,(6*(i))+ 9)] = ss[3] ^= ss[2]; \
}

#define k6e(k,i) \
{   k6ef(k,i); \
    k[v(48,(6*(i))+10)] = ss[4] ^= ss[3]; \
    k[v(48,(6*(i))+11)] = ss[5] ^= ss[4]; \
}

#define kdf6(k,i) \
{   ss[0] ^= ls_box(ss[5],3) ^ t_use(r,c)[i]; k[v(48,(6*(i))+ 6)] = ff(ss[0]); \
    ss[1] ^= ss[0]; k[v(48,(6*(i))+ 7)] = ff(ss[1]); \
    ss[2] ^= ss[1]; k[v(48,(6*(i))+ 8)] = ff(ss[2]); \
    ss[3] ^= ss[2]; k[v(48,(6*(i))+ 9)] = ff(ss[3]); \
    ss[4] ^= ss[3]; k[v(48,(6*(i))+10)] = ff(ss[4]); \
    ss[5] ^= ss[4]; k[v(48,(6*(i))+11)] = ff(ss[5]); \
}

#define kd6(k,i) \
{   ss[6] = ls_box(ss[5],3) ^ t_use(r,c)[i]; \
    ss[0] ^= ss[6]; ss[6] = ff(ss[6]); k[v(48,(6*(i))+ 6)] = ss[6] ^= k[v(48,(6*(i)))]; \
    ss[1] ^= ss[0]; k[v(48,(6*(i))+ 7)] = ss[6] ^= k[v(48,(6*(i))+ 1)]; \
    ss[2] ^= ss[1]; k[v(48,(6*(i))+ 8)] = ss[6] ^= k[v(48,(6*(i))+ 2)]; \
    ss[3] ^= ss[2]; k[v(48,(6*(i))+ 9)] = ss[6] ^= k[v(48,(6*(i))+ 3)]; \
    ss[4] ^= ss[3]; k[v(48,(6*(i))+10)] = ss[6] ^= k[v(48,(6*(i))+ 4)]; \
    ss[5] ^= ss[4]; k[v(48,(6*(i))+11)] = ss[6] ^= k[v(48,(6*(i))+ 5)]; \
}

#define kdl6(k,i) \
{   ss[0] ^= ls_box(ss[5],3) ^ t_use(r,c)[i]; k[v(48,(6*(i))+ 6)] = ss[0]; \
    ss[1] ^= ss[0]; k[v(48,(6*(i))+ 7)] = ss[1]; \
    ss[2] ^= ss[1]; k[v(48,(6*(i))+ 8)] = ss[2]; \
    ss[3] ^= ss[2]; k[v(48,(6*(i))+ 9)] = ss[3]; \
}

AES_RETURN aes_decrypt_key192(const unsigned char *key, aes_decrypt_ctx cx[1])
{   uint_32t    ss[7];
#if defined( d_vars )
        d_vars;
#endif
    cx->ks[v(48,(0))] = ss[0] = word_in(key, 0);
    cx->ks[v(48,(1))] = ss[1] = word_in(key, 1);
    cx->ks[v(48,(2))] = ss[2] = word_in(key, 2);
    cx->ks[v(48,(3))] = ss[3] = word_in(key, 3);

#if DEC_UNROLL == NONE
    cx->ks[v(48,(4))] = ss[4] = word_in(key, 4);
    cx->ks[v(48,(5))] = ss[5] = word_in(key, 5);
    {   uint_32t i;

        for(i = 0; i < 7; ++i)
            k6e(cx->ks, i);
        k6ef(cx->ks, 7);
#if !(DEC_ROUND == NO_TABLES)
        for(i = N_COLS; i < 12 * N_COLS; ++i)
            cx->ks[i] = inv_mcol(cx->ks[i]);
#endif
    }
#else
    cx->ks[v(48,(4))] = ff(ss[4] = word_in(key, 4));
    cx->ks[v(48,(5))] = ff(ss[5] = word_in(key, 5));
    kdf6(cx->ks, 0); kd6(cx->ks, 1);
    kd6(cx->ks, 2);  kd6(cx->ks, 3);
    kd6(cx->ks, 4);  kd6(cx->ks, 5);
    kd6(cx->ks, 6); kdl6(cx->ks, 7);
#endif
    cx->inf.l = 0;
    cx->inf.b[0] = 12 * 16;

#ifdef USE_VIA_ACE_IF_PRESENT
    if(VIA_ACE_AVAILABLE)
        cx->inf.b[1] = 0xff;
#endif

#if defined( AES_ERR_CHK )
    return EXIT_SUCCESS;
#endif
}

#endif

#if defined(AES_256) || defined(AES_VAR)

#define k8ef(k,i) \
{   k[v(56,(8*(i))+ 8)] = ss[0] ^= ls_box(ss[7],3) ^ t_use(r,c)[i]; \
    k[v(56,(8*(i))+ 9)] = ss[1] ^= ss[0]; \
    k[v(56,(8*(i))+10)] = ss[2] ^= ss[1]; \
    k[v(56,(8*(i))+11)] = ss[3] ^= ss[2]; \
}

#define k8e(k,i) \
{   k8ef(k,i); \
    k[v(56,(8*(i))+12)] = ss[4] ^= ls_box(ss[3],0); \
    k[v(56,(8*(i))+13)] = ss[5] ^= ss[4]; \
    k[v(56,(8*(i))+14)] = ss[6] ^= ss[5]; \
    k[v(56,(8*(i))+15)] = ss[7] ^= ss[6]; \
}

#define kdf8(k,i) \
{   ss[0] ^= ls_box(ss[7],3) ^ t_use(r,c)[i]; k[v(56,(8*(i))+ 8)] = ff(ss[0]); \
    ss[1] ^= ss[0]; k[v(56,(8*(i))+ 9)] = ff(ss[1]); \
    ss[2] ^= ss[1]; k[v(56,(8*(i))+10)] = ff(ss[2]); \
    ss[3] ^= ss[2]; k[v(56,(8*(i))+11)] = ff(ss[3]); \
    ss[4] ^= ls_box(ss[3],0); k[v(56,(8*(i))+12)] = ff(ss[4]); \
    ss[5] ^= ss[4]; k[v(56,(8*(i))+13)] = ff(ss[5]); \
    ss[6] ^= ss[5]; k[v(56,(8*(i))+14)] = ff(ss[6]); \
    ss[7] ^= ss[6]; k[v(56,(8*(i))+15)] = ff(ss[7]); \
}

#define kd8(k,i) \
{   ss[8] = ls_box(ss[7],3) ^ t_use(r,c)[i]; \
    ss[0] ^= ss[8]; ss[8] = ff(ss[8]); k[v(56,(8*(i))+ 8)] = ss[8] ^= k[v(56,(8*(i)))]; \
    ss[1] ^= ss[0]; k[v(56,(8*(i))+ 9)] = ss[8] ^= k[v(56,(8*(i))+ 1)]; \
    ss[2] ^= ss[1]; k[v(56,(8*(i))+10)] = ss[8] ^= k[v(56,(8*(i))+ 2)]; \
    ss[3] ^= ss[2]; k[v(56,(8*(i))+11)] = ss[8] ^= k[v(56,(8*(i))+ 3)]; \
    ss[8] = ls_box(ss[3],0); \
    ss[4] ^= ss[8]; ss[8] = ff(ss[8]); k[v(56,(8*(i))+12)] = ss[8] ^= k[v(56,(8*(i))+ 4)]; \
    ss[5] ^= ss[4]; k[v(56,(8*(i))+13)] = ss[8] ^= k[v(56,(8*(i))+ 5)]; \
    ss[6] ^= ss[5]; k[v(56,(8*(i))+14)] = ss[8] ^= k[v(56,(8*(i))+ 6)]; \
    ss[7] ^= ss[6]; k[v(56,(8*(i))+15)] = ss[8] ^= k[v(56,(8*(i))+ 7)]; \
}

#define kdl8(k,i) \
{   ss[0] ^= ls_box(ss[7],3) ^ t_use(r,c)[i]; k[v(56,(8*(i))+ 8)] = ss[0]; \
    ss[1] ^= ss[0]; k[v(56,(8*(i))+ 9)] = ss[1]; \
    ss[2] ^= ss[1]; k[v(56,(8*(i))+10)] = ss[2]; \
    ss[3] ^= ss[2]; k[v(56,(8*(i))+11)] = ss[3]; \
}

AES_RETURN aes_decrypt_key256(const unsigned char *key, aes_decrypt_ctx cx[1])
{   uint_32t    ss[9];
#if defined( d_vars )
        d_vars;
#endif
    cx->ks[v(56,(0))] = ss[0] = word_in(key, 0);
    cx->ks[v(56,(1))] = ss[1] = word_in(key, 1);
    cx->ks[v(56,(2))] = ss[2] = word_in(key, 2);
    cx->ks[v(56,(3))] = ss[3] = word_in(key, 3);

#if DEC_UNROLL == NONE
    cx->ks[v(56,(4))] = ss[4] = word_in(key, 4);
    cx->ks[v(56,(5))] = ss[5] = word_in(key, 5);
    cx->ks[v(56,(6))] = ss[6] = word_in(key, 6);
    cx->ks[v(56,(7))] = ss[7] = word_in(key, 7);
    {   uint_32t i;

        for(i = 0; i < 6; ++i)
            k8e(cx->ks,  i);
        k8ef(cx->ks,  6);
#if !(DEC_ROUND == NO_TABLES)
        for(i = N_COLS; i < 14 * N_COLS; ++i)
            cx->ks[i] = inv_mcol(cx->ks[i]);

#endif
    }
#else
    ss[4] = word_in(key, 4); cx->ks[v(56,(4))] = ff(ss[4]);
    ss[5] = word_in(key, 5); cx->ks[v(56,(5))] = ff(ss[5]);
    ss[6] = word_in(key, 6); cx->ks[v(56,(6))] = ff(ss[6]);
    ss[7] = word_in(key, 7); cx->ks[v(56,(7))] = ff(ss[7]);
    kdf8(cx->ks, 0); kd8(cx->ks, 1);
    kd8(cx->ks, 2);  kd8(cx->ks, 3);
    kd8(cx->ks, 4);  kd8(cx->ks, 5);
    kdl8(cx->ks, 6);
#endif
    cx->inf.l = 0;
    cx->inf.b[0] = 14 * 16;

#ifdef USE_VIA_ACE_IF_PRESENT
    if(VIA_ACE_AVAILABLE)
        cx->inf.b[1] = 0xff;
#endif

#if defined( AES_ERR_CHK )
    return EXIT_SUCCESS;
#endif
}

#endif

#if defined(AES_VAR)

AES_RETURN aes_decrypt_key(const unsigned char *key, int key_len, aes_decrypt_ctx cx[1])
{
    switch(key_len)
    {
#if defined( AES_ERR_CHK )
    case 16: case 128: return aes_decrypt_key128(key, cx);
    case 24: case 192: return aes_decrypt_key192(key, cx);
    case 32: case 256: return aes_decrypt_key256(key, cx);
    default: return EXIT_FAILURE;
#else
    case 16: case 128: aes_decrypt_key128(key, cx); return;
    case 24: case 192: aes_decrypt_key192(key, cx); return;
    case 32: case 256: aes_decrypt_key256(key, cx); return;
#endif
    }
}

#endif

#endif

#if defined(__cplusplus)
}
#endif